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. Author manuscript; available in PMC: 2009 Nov 17.
Published in final edited form as: Invest Ophthalmol Vis Sci. 2008 Oct 3;50(2):691–701. doi: 10.1167/iovs.08-2136

Table 2.

Sensitivities, Specificities, and Cutoffs for TCA Parameters at the Three Specificity Cutoffs, with Pixels Outside Normal Limits Considered, Regardless of Depth of Change from Baseline

Largest Area Cluster (95% CI)
 Largest Volume Cluster (95% CI)
Parameter Sensitivity 0.99 Specificity Cutoff 0.95 Specificity Cutoff 0.90 Specificity Cutoff 0.99 Specificity Cutoff 0.95 Specificity Cutoff 0.90 Specificity Cutoff
CSIZEdisc Sensitivity by disc or GPA 0.639 (0.468–0.810) 0.667 (0.499–0.834) 0.722 (0.562–0.882) 0.639 (0.468–0.810) 0.667 (0.499–0.834) 0.722 (0.562–0.882)
Sensitivity by disc 0.600 (0.360–0.840) 0.600 (0.360–0.840) 0.750 (0.535–0.965) 0.600 (0.360–0.840) 0.600 (0.360–0.840) 0.750 (0.535–0.965)
Specificity 0.952 (0.837–1.00) 0.809 (0.618–1.00) 0.809 (0.618–1.00) 0.952 (0.838–1.00) 0.809 (0.618–1.00) 0.809 (0.618–1.00)
Cutoff 35.0 s-pixels 27.0 s-pixels 20.0 s-pixels 35.0 s-pixels 27.0 s-pixels 20.0 s-pixels
CAREAdisc Sensitivity by disc or GPA 0.611 (0.438–0.784) 0.639 (0.468–0.810) 0.778 (0.628–0.928) 0.611 (0.438–0.784) 0.667 (0.499–0.834) 0.778 (0.628–0.927)
Sensitivity by disc 0.550 (0.307–0.793) 0.600 (0.360–0.840) 0.750 (0.535–0.965) 0.550 (0.307–0.793) 0.600 (0.360–0.840) 0.750 (0.535–0.965)
Specificity 1.00 (0.976–1.00) 0.857 (0.684–1.00) 0.809 (0.618–1.00) 1.00 (0.976–1.00) 0.857 (0.683–1.00) 0.809 (0.618–1.00)
Cutoff 0.074 mm2 0.055 mm2 0.036 mm2 0.074 mm2 0.055 mm2 0.036 mm2
CVOLdisc Sensitivity by disc or GPA 0.250 (0.094–0.405) 0.417 (0.242–0.592) 0.611 (0.438–0.784) 0.250 (0.095–0.405) 0.444 (0.268–0.621) 0.639 (0.468–0.810)
Sensitivity by disc 0.350 (0.116–0.584) 0.550 (0.307–0.793) 0.600 (0.360–0.840) 0.350 (0.116–0.584) 0.600 (0.360–0.840) 0.6500 (0.416–0.884)
Specificity 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.838–1.00) 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.838–1.00)
Cutoff 0.015 mm3 0.010 mm3 0.006 mm3 0.015 mm3 0.010 mm3 0.006 mm3
CSIZE% Sensitivity by disc or GPA 0.389 (0.216–0.562) 0.500 (0.323–0.677) 0.750 (0.595–0.905) 0.389 (0.216–0.562) 0.500 (0.322–0.677) 0.750 (0.595–0.905)
Sensitivity by disc 0.350 (0.116–0.584) 0.450 (0.207–0.693) 0.750 (0.535–0.965) 0.350 (0.116–0.584) 0.450 (0.207–0.693) 0.750 (0.535–0.965)
Specificity 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.809 (0.618–1.00) 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.809 (0.618–1.00)
Cutoff 5.21% 3.98% 1.96% 5.21% 3.98% 1.96%
CSIZEtotal Sensitivity by disc or GPA 0.333 (0.165–0.501) 0.389 (0.216–0.562) 0.500 (0.323–0.677) 0.333 (0.165–0.501) 0.389 (0.215–0.562) 0.472 (0.295–0.649)
Sensitivity by disc 0.250 (0.035–0.465) 0.350 (0.116–0.584) 0.500 (0.256–0.744) 0.250 (0.035–0.465) 0.350 (0.116–0.584) 0.450 (0.207–0.693)
Specificity 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.809 (0.618–1.00) 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.809 (0.618–1.00)
Cutoff 164.0 s-pixels 135.0 s-pixels 120.0 s-pixels 164.0 s-pixels 135.0 s-pixels 120.0 s-pixels
CAREAtotal Sensitivity by disc or GPA 0.333 (0.165–0.501) 0.444 (0.268–0.621) 0.500 (0.323–0.677) 0.417 (0.242–0.592) 0.417 (0.242–0.592) 0.444 (0.268–0.621)
Sensitivity by disc 0.250 (0.035–0.465) 0.400 (0.160–0.640) 0.450 (0.207–0.693) 0.250 (0.035–0.465) 0.350 (0.116–0.584) 0.350 (0.116–0.584)
Specificity 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.837–1.00) 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.837–1.00)
Cutoff 0.355 mm2 0.288 mm2 0.260 mm2 164.0 s-pixels 135.0 s-pixels 120.0 s-pixels
CVOLtotal Sensitivity by disc or GPA 0.222 (0.072–0.372) 0.222 (0.072–0.372) 0.333 (0.165–0.501) 0.222 (0.072–0.372) 0.222 (0.072–0.372) 0.333 (0.165–0.501)
Sensitivity by disc 0.250 (0.035–0.465) 0.250 (0.035–0.465) 0.350 (0.116–0.584) 0.250 (0.035–0.465) 0.250 (0.035–0.465) 0.350 (0.116–0.584)
Specificity 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.837–1.00) 1.00 (0.976–1.00) 1.00 (0.976–1.00) 0.952 (0.837–1.00)
Cutoff 0.040 mm3 0.033 mm3 0.025 mm3 0.040 mm3 0.033 mm3 0.025 mm3

Cutoffs were determined using permuted longitudinal healthy data with 1000 permutations. CSIZEdisc, the number of superpixels (s-pixels) within a cluster within the optic disc margin; CAREAdisc, area of a cluster (mm2) within the optic disc margin; CVOLdisc, volume of a cluster (mm3) within the optic disc margin; CSIZE%, cluster size in superpixels expressed as percentage of optic disc area; CSIZEtotal, the number of superpixels within the whole image field of view; CAREAtotal, area of cluster (mm2) within the whole image field of view; CVOLtotal, volume of a cluster (mm3) within the whole image field of view.